While resting at East Beach in Charlestown, RI, at the above date and time, enjoying a beautiful clear blue sky and warm sun, I noticed a twin engine plane, with rows of windows on each side, and having pods at the wing tips (fuel?), white in color, flying a continuous loop over the beach, circling, slowly, then going away to the west, but coming right back. I thought this continuous pattern of low flying, low level observation, was odd, especially after the fourth time of it flying right over me. The beach was almost unpopulated, it being a Monday, and it being a very long 3 mile stretch of beach, and I was down about a quarter mile, away from most people at the entrance. So, there were about fifty people on the beach but all but me and three other people were at the entrance. I had my binoculars with me, so I decided to get a close up of the plane as it kept flying directly over me in its circling. I first noticed no FAA identifying markings of any ki! nd on it...no numbers or letters, etc. I saw only one small blinking red light at the tip of the rear 'fin' (aeleron?), and then I noticed a conspicuous large dark spot, like an oval camera lens, on the underside of the fuselage behind the wings. I then thought this was some kind of secret government plane taking photos. The plane continued its pattern of circling over the beach where I was, so I decided to leave and head for my trunk in the parking lot. The plane made another pass, this time right over me in the parking lot, whereupon I took out my binoculars again to get another close look....while looking at the bottom of the 'plane' I was shocked to see a quick flash of green light, very bright, come from what I thought previously was a camera lens! This quick flash of green light was directed toward me, as if they were letting me know that they saw me, and maybe even were reading my thoughts. It freaked me out, as I said, 'oh my God.' It was so unnatural a thing ! that it did. This was no ordinary plane by any means, but a ! craft ma squerading as a twin engine plane, but having a whole different propulsion and technology, as in the green light underneath. There were no wing tip lights or any thing which I thought should be on a registered FAA plane. It made a sound very similar to a prop plane, but different. The windows were all blacked out, including the cockpit windows. I then left in my truck and drove to Walmart about 5 miles away. After shopping for a half hour I decided to go back to the beach parking lot to see if the 'plane' was still there in its same circling pattern, and it was! It flew a couple hundred feet above the shoreline, then circled over the salt pond in back of the beach, headed West again, and then repeated this pattern, over and over...nothing normal about it. This is just one more strange aircraft sighting in this area. My belief is that aliens are masquerading their craft as jets, passenger jets, and small prop/commuter planes like this one. The strange 'camera' spot/l! ens that flashed bright green at me while I was looking at it through the binoculars was the strangest event, and a bit intimidating...maybe that was 'their' intent. Something very strange in going on in southern Rhode Island...very strange. By the way, the flashing green light did not emit a beam that I could see.